Synthesis and therapeutic potential of stimuli-responsive metal-organic frameworks

Nanotechnology, as a progressing field of science, is constantly expanding its role in biomedicine by introducing novel nanoplatforms over time. Nanoscaled metal-organic frameworks (NMOFs) are porous hybrid solids made of organic ligands and metal ions that offer a powerful potential to revolutionize traditional nanocarriers due to their tunable structural features, high surface area, adjustable pore size, facile synthesis, biocompatibility, highly versatile composition, and high chemical stability. Among various types of NMOFs, the stimuli-responsive ones are efficient candidates for biomedical applications, because they are designed to specifically change their property upon exposure to interior stimuli in target tissues (e.g., pH and redox reaction triggering agents), or external stimuli like temperature, light, and magnetic field. In this review, to fully address recent advances in the field of stimuli-responsive MOF nanocarriers, we have present the basic chemistry behind the stimuli-responsive mechanisms of MOFs. In addition, recent progresses on MOF-based stimuli-responsive systems, including those responding to a single stimulus and multiple stimuli, are discussed, providing an innovative vision for the design of multifunctional smart MOFs that can respond to different triggers.